The touching reason Tom Arnold lost 89 pounds

Actor says the birth of his son convinced him that he 'needed to live as long as he could.'

After years of battling weight gain and dealing with depression, Tom Arnold is kicking off 2014 lighter, healthier and more inspired than ever to do everything possible to keep it that way.

The 54-year-old former "Sons of Anarchy" star credits the birth of his first child, Jax, with putting him on the fast-track last April to drop the pounds and exercise. "Something inside of me changed. I knew I needed to live as long as I could," he tells People. "The moment I saw [Jax], I realized he deserves the best."

Arnold immediately dropped bread, sweets, and a daily habit of drinking 15 cans of diet soda. He also incorporated cardio, circuit-training and abdominal workouts. As a result, he's lost more than 89 pounds since April.

He said: "I have tons more energy to play with my son." You can see the dramatic difference in the photos below (and this his wife, Ashley Groussman, with him in the photo at right.)